This PR adds server-side support for dedicated 'unsolved goals' and
'goals accomplished' diagnostics that will have special support in the
Lean 4 VS Code extension. The special 'unsolved goals' diagnostic is
adapted from the 'unsolved goals' error diagnostic, while the 'goals
accomplished' diagnostic is issued when a `theorem` or `Prop`-typed
`example` has no errors or `sorry`s. The Lean 4 VS Code extension
companion PR is at leanprover/vscode-lean4#585.
Specifically, this PR extends the diagnostics served by the language
server with the following fields:
- `leanTags`: Custom tags that denote the kind of diagnostic that is
being served. As opposed to the `code`, `leanTags` should never be
displayed in the UI. Examples introduced by this PR are a tag to
distinguish 'unsolved goals' errors from other diagnostics, as well as a
tag to distinguish the new 'goals accomplished' diagnostic from other
diagnostics.
- `isSilent`: Whether a diagnostic should not be displayed as a regular
diagnostic in the editor. In VS Code, this means that the diagnostic is
displayed in the InfoView under 'Messages', but that it will not be
displayed under 'All Messages' and that it will also not be displayed
with a squiggly line.
The `isSilent` field is also implemented for `Message` so that silent
diagnostics can be logged in the elaborator. All code paths except for
the language server that display diagnostics to users are adjusted to
filter `Message`s with `isSilent := true`.
as #4527 describes there is inconsistency between `by`, `case` and
`next` on the one hand who, if the goal isn’t closed, put squiggly
underlines on the first line, and `.`, which so far only squiggled the
dot (which is a very short symbol!)
With this change the same mechanism as used by `case`, namely
`withCaseRef`, is also used for `.`.
There is an argument for the status quo: The `.` tactic is more commonly
used
with further tactics on the same line, and thus there is now a higher
risk that
the user might think that the first tactic is broken. But
* the same argument does apply to `by` and `case` where there was an
intentional
choice to do it this way
* consistency and
* a squiggly line just under the short `.` is easy to miss, so it is
actually
better to underlining more here (at least until we have a better way to
indicate incomplete proofs, which I have hopes for)
Fixes#4527, at least most of it.
